Over the years, industry has been unable to rely on an economical, maintenance-free and accurate system to measure the level of liquids in tanks. Level measurement systems are used to operate alarm gauges which indicate maximum and minimum liquid levels and control pumps, lights and signals.
Most level measurement systems use some type of floating device. The classical floating device uses a control system responsive only to the maximum tank filling level. Alternatively, there are also very sophisticated electronic level measurement systems in which reed switches in contact with the liquid ensure measurements which vary according to the salinity of the liquid.